Webster's Revised Unabridged Dictionary · 1913

Uncertain

Uncertain (un*sẽr"tin) , adjective

[Prefix un- not + certain. Compare Incertain.]

1.
Not certain; not having certain knowledge; not assured in mind; distrustful. — Chaucer
Man, without the protection of a superior Being,... is uncertain of everything that he hopes for. — Tillotson
2.
Irresolute; inconsonant; variable; untrustworthy; as, an uncertain person; an uncertain breeze.
O woman! in our hours of ease, Uncertain, coy, and hard to please! — Sir W. Scott
3.
Questionable; equivocal; indefinite; problematical.
The fashion of uncertain evils. — Milton
From certain dangers to uncertain praise. — Dryden
4.
Not sure; liable to fall or err; fallible.
Soon bent his bow, uncertain in his aim. — Dryden
Whistling slings dismissed the uncertain stone. — Gay

Uncertain , transitive verb

[1st pref. un- + certain; or from uncertain, a.]

To make uncertain. [Obsolete] — Sir W. Raleigh